Collision avoidance system for two crane gantries - uses trolley poles contacting overhead cable for mechanical detection of separation of two gantries

摘要

The device described is used to avoid collision between two gantries (2, 3) travelling over the same track (1). Its electrical operation is controlled by mechanical detection of the distance (d) separating the engines. This mechanical detection is effected using a conductor (4) held parallel to the track (1) and above it and which operates in conjunction with a fixed trolley-pole (5, 6) on each gantry. The trolley-pole (5) on one gantry is higher than on the other (6). Electrical equipment is provided on each gantry, and when voltage is applied to the equipment on one gantry, a circuit comprising the overhead conductor, the trolley poles, the track itself, and the equipment on the other is try, is closed. In this way, a connection is established between the control switch and the drive motor of the gantry under power, via a suitable relay.